The Carlyle Group is planning to invest $500 million in Beats Electronics, which would give the dull private-equity firm a minority stake in Dr Dre’s pet project, reports the Wall Street Journal.

It is interesting to note that it is still unclear how much Carlyle would own, but since it is paying $500 for a minority stake, it seems they value Beats at over $1 billion, which might not go down well with HTC.

Just before it tanked, HTC bought a 50-percent stake in Beats, which it eventually sold back to the headphone. The deal wasn’t welcomed by HTC shareholders who reckoned the money could have been used elsewhere and in the end the naysayers were right. Ironically, Beats is now doing a lot better than HTC. Last year its revenue hit $1 billion, up from $200 million in 2010.

But what on earth does Carlyle want with Beats? Carlyle is not new to tech, it has already made sizable investments in Freescale Semiconductor, Booz Allen Hamilton, Getty Images and Nielsen. Carlyle knows a good opportunity when it sees one and it can afford throw more cash at Beats to keep it growing.

Consumer electronics are still doing fine and the mobile craze means there are a lot more people looking for aftermarket headphones for their smartphones and tablets.